The response of pituitary gonadotropes to synthetic LRF in children with glucocorticoid-treated congenital adrenal hyperplasia: lack of effect of intrauterine and neonatal androgen excess

Previous studies have demonstrated that the secretory reserve of the pituitary gland during childhood and adolescence is characterized by an age-related increase in LH secretion and a sex dichotomy of FSH secretion evoked by LRF. To determine if prenatal and neonatal androgen excess alters hypothalamic-pituitary-gonadal function, as in the neonatally androgenized rodent, we assessed pituitary sensitivity to 100 mug synthetic LRF in 9 girls and 2 boys with glucorticoid-treated congenital virilizing adrenal hyperplasia (CAH). In the 7 prepubertal girls with CAH, plasma LH following LRF rose to 2.0 plus or minus 0.4 (SE) ng/ml (LER 960) and did not differ from normal prepubertal children (1.7 plus or minus 0.1) and was lower (P less than 0.002) than in normal pubertal children (4.9 plus or minus 0.3). The 2 pubertal girls had LH rises in the pubertal range. In the 2 boys with CAH, the one with the more advanced bone age, 11-6/12 yr, developed true precocious puberty following initiation of cortisone treatment and had a pubertal LRF-evoked LH release on 3 occasions; the more immature boy, bone age 10, had a prepubertal LH rise. In the 7 prepubertal girls with CAH, plasma FSH rose to 8.1 plus or minus 1.6 (SE) ng/ml (LER 869), which did not differ from normal prepubertal girls (5.3 plus or minus 1.9), but was significantly (P less than 0.001) greater than in normal prepubertal boys (2.9 plus or minus 0.4). In these girls with CAH, basal plasma T (27.4 plus or minus 4.0 (SE) ng/dl) and 17-OHP (2703 plus or minus 1143 (SE) ng/dl) were greater than in prepubertal children, but plasma E1 and E2 were in the normal range. The pubertal boy had plasma T, E1, and E2 levels appropriate for his degree of sexual maturation. The results suggest: (1) age-related LH secretion evoked by LRF in glucocorticoid-treated CAH is appropriate for skeletal maturation; (2) the sex dichotomy of FSH secretion following LRF is preserved in CAH despite intrauterine and variable postnatal exposure to excess androgen and continuing slightly elevated plasma T during childhood; and (3) precocious puberty may follow initiation of cortisone treatment in a child with CAH whose bone age and secretory reserve of pituitary gonadotropins are in the pubertal range.